Process for preparing 1,2-dehydro steroids

ABSTRACT

Disclosed and claimed is an improved microbial bioconversion to produce 1,2-dehydro steroids from their corresponding 1,2-saturated derivatives.

CROSS REFERENCE TO RELATED APPLICATION

This is a continuation-in-part of our pending application Ser. No. 403,949, filed on July 30, 1982 and now abandoned.

BACKGROUND OF THE INVENTION

The first therapeutic use of corticosteroids was demonstrated in the 1950's with the introduction of cortisone acetate treatment for rheumatoid arthritis. Further studies demonstrated that the insertion of unsaturation into the 1,2 position of hydrocortisone and cortisone caused the resultant steroids, prednisolone and prednisone, to have enhanced potency and to cause less drug-induced salt retention. Subsequently, most other steroids used for the treatment of corticoid-responsive diseases have been synthesized so that they contain a double bond in the 1,2 position of the steroid molecule. In 1977, two U.S. patents were issued which represent new approaches to the synthesis of corticosteroids from sterol precursors. U.S. Pat. No. 4,035,236 covers a process for preparing 9α-hydroxyandrostenedione via fermentation of sitosterol, stigmasterol, or cholesterol. U.S. Pat. No. 4,041,055 discloses a general process for the synthesis of medically useful corticosteroids from this androstene. Intermediates covered in this chemisty can possess a 3-keto-Δ⁴,9(11) configuration.

Following are prior art methods which disclose the bioconversion of 1,2-saturated steroids to their corresponding 1,2-dehydro steroids:

U.S. Pat. No. 2,837,464 "Process for Production of Dienes by Corynebacterium".

Description of 1-dehydrogenation of steroids in fermentation beers by Arthrobacter (Corynebacterium) simplex.

U.S. Pat. No. 3,360,439 entitled "Process for Preparing 1-dehydro Steroids".

Description of 1-dehydrogenation of steroids by use of A. simplex cells pretreated with a lower alkanol or lower alkanone such as acetone before mixing with the substrate and a hydrogen carrier.

Charney, W. and Herzog, H. 1967. Microbial Transformation of Steroids. Academic Press, Inc., New York, pp 4-9, 236-261.

Historical background on steroid bioconversions and taxonomic listing of microorganisms known to carry out 1-dehydrogenation.

The prior art does not disclose or suggest the subject improved process.

BRIEF SUMMARY OF THE INVENTION

By using air-dried or heat-dried microbial cells that are capable of catalyzing 1-dehydrogenation of steroids, there is obtained a more efficient conversion of 1,2-saturated steroids to their corresponding 1,2-dehydro derivatives than is obtainable by the best known prior art process. This greater efficiency is manifested by

(1) a faster rate of conversion while also having much reduced or totally eliminated levels of other steroid modifying enzymes which thus gives better yields of the desired products, and

(2) the use of higher substrate levels of certain steroid compounds than is possible in prior art processes. The net effect is that the subject process gives a better yield of desired product than is obtainable by the prior art.

DETAILED DESCRIPTION OF THE INVENTION Microorganism

The microbes which can be used in the subject process are any of the numerous well-known microbes which are known as 1-dehydrogenators. Such microbes are listed in Charney, W. and Herzog, H. 1967. Microbial Transformation of Steroids. Academic Press, Inc., New York.

The bacteria that 1-dehydrogenate steroids fall within two general groups establishes in Bergey's Manual of Determinative Biology, 8th edition. The procedure described herein has been successfully demonstrated for species from Arthrobacter and Cornebacterium, genera that are included in "Part 17. Actinomycetes & Related Organisms". The 1-dehydrogenating species of several other genera in Part 17, such as Nocardia, Mycobacterium, Streptomyces and Bacterium are probably useful.

Two microorganisms available to the public which are known to 1-dehydrogenate steroids have been demonstrated to lend themselves useful for this type of process. Bacterium cyclooxydans, included in U.S. Pat. No. 3,065,146 as a 1-dehydrogenator-ATCC number 12673, has been examined as a useful microorganism. A bacterium that has been used much more extensively for the 1-dehydrogenation of steroids is Arthrobacter simplex, ATCC 6946, which is disclosed in U.S. Pat. No. 2,837,464. Thus, much of the following will use this microorganism to exemplify the invention process. It should be understood, however, that the subject process also covers the use of any 1-dehydrogenating microbe.

Growth of the Microorganism--The microorganisms are grown in an aqueous nutrient medium containing:

(a) inorganic compounds such as nitrate or ammonium salts or organic nitrogenous compounds (yeast extract, peptone, cornsteep liquor, etc.) to provide nitrogen for growth.

(b) a carbon and energy source such as carbohydrates and sugar derivatives, oil, fatfty acids and their methyl esters, alcohols, amino acids or organic acids.

(c) ions and trace elements such as sodium, potassium, magnesium, phosphate, sulfate, manganese, copper, cobalt, molybdenum, etc. in levels supplied by tap water or by the less refined medium ingredients (such as cornsteep liquor).

The organisms require oxygen present in the atmosphere for growth. The temperature range for growth in 10°-45° C. with an optimum of 28°-37° C. for A. simplex. The optimum pH for growth is around neutrality.

Production of the Steroid-1-Dehydrogenase--The cells are induced for steroid-1-dehydrogenase activity by the addition of a 1,2-saturated 3-keto-steroid compound such as androsta-4- ene-3,17-dione or cortisone acetate at a level at 0.005% w/v of the medium or greater. In the presence of the inducer, incubation is continued for a period of at least 6 hours before the cells are harvested for drying.

The inducer can be added at any point during the growth cycle. Cultures grown on nutrients such as lard oil will start synthesizing the steroid-1-dehydrogenase rapidly while cultures grown on glucose require substrate depletion before enzyme synthesis will occur. Incubation is continued for a period of 6 or more hours after the inducer is added, then the cells are harvested for drying.

Procedure for Recovering Cells--Cells are separated from the nutrient medium and concentrated by conventional means such as centrifugation, or flocculation, and filtration and ultrafiltration. The separated cells are then dried by placing under reduced pressures at 1°-85° C. (55°-75° preferred), by air drying with heat, or by spray drying, or by tumble drying until a moisture content in the range of about 1 to about 10%. A moisture content of about 5% is preferred. Cells are stored at 5° C. until used for bioconversions. Active dried cells can also be prepared by immobilizing dried cells by standard techniques, such as entrapment within polyacrylamide gel and collagen or covalent coupling of the cells to a polyelectrolyte carrier as described in Methods in Enzymology, Vol. XLIV, 1976, Academic Press, Inc., New York, pp 11-317.

Bioconversion Process--The bioconversion is accomplished by exposure of the prepared cells to the steroid substrate. Typically, the cells and steroid are suspended in a weakly buffered aqueous solution with a pH in the range of pH 6-pH 10 with an optimum of ph 7.25-8.5. The amount of cells can range from 0.1-50 g/liter, the steroid is added at a weight ratio of 0.05 to 5.0 (steroid:cells). Cells levels of 8-10 g/liter with 5-10 g/liter steroid are preferred. An exogenous electron carrier is added in catalytic amounts, (e.g., 5×10⁻⁴ M menadione) to stimulate the reaction. Useful compounds include menadione (2-methyl-1,4-napthoquinone), phenazine methosulfate, dichlorophenol-indophenol, 1,4-napthoquinone, menadione bisulfite, ubiquinones (Coenzyme Q), and vitamin K-type compounds. The mixtures incubated 10-14 days at a temperature range of 5°-45° C. During incubation, the mixture has access to molecular oxygen and is preferably stirred. The rate of 1-dehydrogenation typically decreases with time. The bioconversion can proceed to 98-99% of completion in less than 24 hours using 10 g/liter substrate.

Examples of the various procedures that can be used include:

(a) Suspension of the steroid and menadione in a weakly buffer aqueous solution, followed by addition of the dried cells. Surfactants such as Tween 80 can be added in low concentration, e.g., 0-5%, to aid in steroid suspension.

(b) Suspension of the cells in an aqueous buffer system, followed by addition of the electron carrier dissolved in ethanol, methanol, acetone (not greater than 5% of final volume). The steroid substrate can be added as a dry powder or dissolved (suspended) in a miscible organic solvent such as dimethyl formamide, ethanol, methanol, acetone, dimethyl sulfoxide, or an immiscible organic solvent such as toluene.

(c) Rehydration of the dried cells in a small volume of buffer followed by the addition of more buffer or of organic solvents. Ethanol, acetone, xylene, butyl acetate, methylene chloride, or toluene, etc. is added to give a final organic solvent content of 0-95% (vol/vol). The steroid and electron carrier are added to initiate the reaction.

Substrate Range--Compounds that are useful in the practice of this invention belong to the 3-keto-Δ⁴ -androstene and 3-keto-Δ⁴ -pregnene series of steroids. It is recognized that substrates for the steroid-1-dehydrogenase will have saturation between carbons C1 and C2 of the A ring, and will have a hydroxyl or keto group at position 3 on the A ring. Members of the androstene series include:

(1) androsta-4-ene-3,17-dione and

androsta-4,9(11)-diene-3,17-dione and its 6α-fluoro, 6α-methyl, or 16-methyl derivatives.

Among the steroids of the 3-keto-Δ⁴ -pregnene series which can be used are:

1. 17α-hydroxypregn-4-ene-20-yn-3-one and its 16-methyl derivatives;

2. 11β, 21-dihydroxy-pregn-4,17(20)-diene-3-one and its 6α-methyl derivative;

3. 20-chloro-pregn-4,9(11),17(20)-triene-21-al-3-one;

4. several groups of 3,20-diketo-Δ⁴ -pregnenes, including

(a) 11,17,21-trihydroxy compounds, such as hydrocortisone and its 6α-methyl derivative;

(b) 9β,11β-epoxy-17,21-dihydroxy compounds, such as 9β,11β-epoxy-17,21-dihydroxy-16β-methyl-pregn-4-ene-3,20-dione;

(c) 3,20-diketo-4,9(11)-pregnedienes such as 17α,21-dihydroxy-pregn-4,9(11)-diene-3,20-dione and its 16α-methyl, 16β-methyl or 16α-hydroxy derivatives or 17α-acetate ester;

(d) 3,20-diketo-4,9(11), 4,9(11),16-pregnetrienes, such as 21-hydroxy-pregn-4,9(11), 16-triene-3,20-dione and its 6α-fluoro derivative.

The 21-ester derivatives of those steroids containing a 21-hydroxyl group (#2 and #4) serve as substrates also. The preferred 21-esters consist of lower alkyl or aryl groups such as lower fatty acids, e.g. acetic acid, and monocyclic carboxylic acids, e.g., benzoic acid.

The bioconversion products and unconverted substrate can be recovered from the mixtures by conventional means. Steroids are typically recovered by filtration, followed by extraction of the filter cake with an organic solvent, such as acetone or methylene chloride. Alternatively, the while bioconversion mixture can be extracted by mixing with a water immiscible solvent such as butyl acetate or methylene chloride. The product is then crystallized from the organic solvent.

Following are the results of different bioconversions which demonstrate the superiority of the invention process over prior art processes. The bioconversions were conducted using the conditions detailed above.

EXAMPLE 1 Preparation of dried cells

Bacterium cyclo-oxydans (ATCC 12673) was inoculated into shake flasks containing a medium of cerelose, peptone, and corn steep liquor (6 g/l of each) pH 7.0. The cultures were incubated on a rotary shaker at 28° C. until glucose exhaustion occurred. Cortisone acetate (0.5 g/l) was added at that time and the flasks incubated an additional 16 hrs. The cells were harvested by centrifugation, washed twice with water then placed in a low vacuum over at 45° C. until dry.

Bioconversion of 6α-methyl hydrocortisone

One-half gram of dried cells, prepared as described above, were rehydrated in 50 ml of 50 mM phosphate buffer pH 7.5 with stirring. Menadione was added to the cell suspension as an ethanolic solution (8.6 mg/ml ethanol) at a level of 0.025 ml/50 ml. The substrate was added as a dimethylformamide (DMF) solution (100 mg 6α-methyl hydrocortisone/ml DMF) to a final bioconversion concentration of 0.5 g/liter. The mixture was incubated at 28° C. with agitation. After 4 hrs incubation, the steroid was 91% converted. The 6α-methyl prednisolone was recovered by conventional means.

EXAMPLE 2 Androsta-1,4,9(11)-triene-3,17-dione Production (a) Preparation of biocatalyst

Arthrobacter simplex (ATCC 6946) was grown in shake flasks in a medium containing 6 g/l glucose, 6 g/l corn steep liquor, and 6 g/l of spray dried lard water. The cultures were incubated at 28° C. on a rotary shaker until glucose depletion occurred. At that time, cortisone acetate (0.15 g/l) was added to induce steroid-1-dehydrogenase synthesis. After overnight incubation, the cells were harvested by low speed centrifugation. The cell pellets were placed in a 55° C. low vacuum oven for 24 hr to dry. Twenty-four hours later, the dried material was transferred to an air-tight container and stored at 50° C. until it was needed for a bioconversion.

(b) Bioconversion of androsta-4,9(11)-diene-3,17-dione

Dried cells (10 g/l) were dehydrated in 50 mM phosphate buffer pH 7.5 by stirring for 30 minutes. Menadione was then added to cell suspension as a dry powder to a final concentration of 86 mg/liter. Micronized androsta-4,9(11)-diene-3,17-dione was slurried in dimethylformamide and added to the bioconversion mixture at a level of 2.5 g steroid/liter and 2% (v/v) DMF. The mixture was incubated at 31° C. with agitation in the presence of air for 24 hr. After completion of the incubation, androsta-1,4,9(11)-triene-3,17 dione was recovered by conventional means.

EXAMPLE 3

The following steroidal compounds were exposed to dried cells of A. simplex in accordance with the conditions described in the preceding example in order to obtain the corresponding 1,2-dehydro derivatives:

    ______________________________________                                         No.     Name                                                                   ______________________________________                                         1.      androsta-4-ene-3,17-dione                                              2.      6α-fluoro-androsta-4,9(11)-diene-3,17-dione                      3.      6α-methyl-androsta-4,9(11)-diene-3,17-dione                      4.      16β-methyl-androsta-4,9(11)-diene-3,17-dione                      5.      17α-hydroxypregn-4-ene-20-yn-3-one                               6.      17α-hydroxypregn-4,9(11)-diene-20-yn-3-one                       7.      17α-hydroxy-16β-methyl-pregn-4,9(11)-diene-2O-yn-                   3-one                                                                  8.      11β,21-dihydroxy-pregn-4,17(20)-diene-3-one                       9.      21-acetoxy-11β-hydroxy-pregn-4,17(20)-diene-3-one                 10.     6β-methyl-11β,21-dihydroxy-pregn-4,17(20)-diene-3-                   one                                                                    11.     20-chloro-pregn-4,9(11),17(20)-triene-21-al-3-one                      12.     hydrocortisone                                                         13.     6α-methyl hydrocortisone                                         14.     21-acetoxy-11β,17-dihydroxy-16β-methyl-pregn-4-                      ene-3,20-dione                                                         15.     21-acetoxy-9α-fluoro-11β,17-dihydroxy-16β-methyl-              8                                                                              pregn-4-ene-3,20-dione                                                 16.     21-acetoxy-9β,11β-epoxy-17-hydroxy-16β-methyl-                  pregn-4-ene-3,20-dione                                                 17.     21-acetoxy-17-hydroxy-pregn-4,9(11)-diene-3,20-                                dione                                                                  18.     21-acetoxy-16α,17-dihydroxy-pregn-4,9(11)-diene-                         3,20-dione                                                             19.     21-acetoxy-17-hydroxy-16α-methyl-pregn-4,9(11)-                          diene-3,20-dione                                                       20.     21-benzoyloxy-17-hydroxy-16β-methyl-pregn-4,9(11)-                        diene-3,20-dione                                                       21.     21-acetoxy-17-hydroxy-16β-methyl-pregn-4,9(11)-                           diene-3,20-dione                                                       22.     21-acetoxy-pregn-4,9(11),16(17)-triene-3,20-dione                      23.     21-acetoxy-6α-fluoro-pregn-4,9(11),16-triene-3,20-                       dione.                                                                 ______________________________________                                    

The corresponding products obtained from the conversions are as follows:

    ______________________________________                                         No.     Products                                                               ______________________________________                                         1a      androsta-1,4-diene-3,17-dione                                          2a      6α-fluoro-androsta-1,4,9(11)-triene-3,17-dione                   3a      6α-methyl-androsta-1,4,9(11)-triene-3,17-dione                   4a      16β-methyl-androsta-1,4,9(11)-triene-3,17-dione                   5a      17α-hydroxypregn-1,4-diene-20-yn-3-one                           6a      17α-hydroxypregn-1,4,9(11)-triene-20-yn-3-one                    7a      17α-hydroxy-16β-methyl-pregn-1,4,9(11)-triene-20-                   yn-3-one                                                               8a      11β,21-dihydroxy-pregn-1,4,17(20)-triene-3-one                    9a      21-acetoxy-11β-hydroxy-pregn-1,4,17(20)-triene-3-                         one and                                                                        11β,21-dihydroxy-pregn-1,4,17(20)-triene-3-one                    10a     6α-methyl-11β,21-dihydroxy-pregn-1,4,17(20)-                        triene-3-one                                                           11a     20-chloro-pregn-1,4,9(11),17(20)-tetraene-21-al-3-                             one                                                                    12a     prednisolone                                                           13a     6α-methyl-prednisolone                                           14a     21-acetoxy-11β,17-dihydroxy-16β-methyl-pregn-1,4-                    diene-3,20-dione and                                                           11β,17,21-trihydroxy-16β-methyl-pregn-1,4-diene-                     3,20-dione                                                             15a     21-acetoxy-9α-fluoro-11β,17-dihydroxy-16β-methyl-              6                                                                              pregn-1,4-diene-3,20-dione and                                                 9α-fluoro-11β,17,21-trihydroxy-16β-methyl-pregn-               1,4-diene-3,20-dione                                                   16a     21-acetoxy-9β,11β-epoxy-17-hydroxy-16β-methyl-                  pregn-1,4-diene-3,20-dione and                                                 9β,11β-epoxy-17,21-dihydroxy-16β-methyl-pregn-1,4-              .                                                                              diene-3,20-dione                                                       17a     21-acetoxy-17-hydroxy-pregn-1,4,9(11)-triene-3,20-                             dione and 17,21-dihydroxy-pregn-1,4,9(11)-                                     triene-3,20-diene                                                      18a     21-acetoxy-16α,17-dihydroxy-pregn-1,4,9(11)-                             triene-3,20-dione and                                                          16α,17,21-trihydroxy-pregn-1,4,9(11)-triene-3,20-                        dione                                                                  19a     21-acetoxy-17-hydroxy-16α-methyl-pregn-1,4,9(11)-                        triene-3,20-dione and                                                          17,21-dihydroxy-16α-methyl-pregn-1,4,9(11)-triene-                       3,20-dione                                                             20a     21-benzoyloxy-17-hydroxy-16β-methyl-pregn-                                1,4,9(11)-triene-3,20-dione                                            21a     21-acetoxy-17-hydroxy-16β-methyl-pregn-1,4,9(11)-                         triene-3,20-dione and                                                          17,21-dihydroxy-16β-methyl-pregn-1,4,9(11)-triene-                        3,20-dione                                                             22a     21-acetoxy-pregn-1,4,9(11),16-tetraene-3,20-dione                              and                                                                            21-hydroxy-pregn-1,4,9(11),16-tetraene-3,20-dione                      23a     21-acetoxy-6α-fluoro-pregn-1,4,9(11),16-                                 tetraene-3,20-dione and                                                        6α-fluoro-21-hydroxy-pregn-1,4,9(11),16-tetraene-                        3,20-dione.                                                            ______________________________________                                    

EXAMPLE 4

Two different steroids were bioconverted with cells of A. simplex in fermentation beer and with dried A. simplex cells. After each bioconversion was judged to be finished (as indicated by no further decrease in residual levels), the steroid in the mixture was extracted and isolated to provide yield data for each condition. The following table summarizes those results.

    __________________________________________________________________________     Comparison of Isolation Yields Obtained from                                   Different Types of Bioconversions                                                          Type of Chemical Yield of                                                                         % Δ'                                                                           %                                         Substrate   Bioconversion                                                                          Useful Steroid (a)                                                                        Compound                                                                             Residual                                                                            Comments                             __________________________________________________________________________      ##STR1##   Fermentation                                                                           77.2% 1st crop  2.8% 2nd crop                                                               2.6  87.4  89.6                                                                         Poor 1- dehydro- genation             10 g/liter Dried Cell                                                                             82.6% 1st crop                                                                            100.0 --                                                             9.9% 2nd crop                                                                             95.5  5.0                                       ##STR2##   Fermentation                                                                           18.1 1st crop No 2nd crop obtained                                                         59.1 40.9 (b)                                   8 g/liter  Dried Cells                                                                            79.6% 1st crop                                                                             97.8  2.1                                                          No 2nd crop obtained                                       __________________________________________________________________________      (a) Useful steroid is defined as either the Δ' compound which can b      used in further synthesis or the 1,2dihydro substrate which can be             recycled into another bioconversion to produce product.                        (b) Considerable amounts of other undesirable steroid molecules were also      recovered.                                                               

EXAMPLE 5

Arthrobacter simplex was grown in a 5-liter "Microferm" fermentor, induced for steroid-1-dehydrogenase synthesis, and harvested by centrifugation. Portions of the recovered cell paste were subjected to two different preparation methods. The first was the procedure disclosed herein which consisted of drying the cells under reduced pressure at 55° C. The second method was the procedure recommended in U.S. Pat. No. 3,360,439 for preparation of acetone-dried cells. Cells were mixed with acetone, harvested and dried at 5° C. under reduced pressure. The dried cell preparations were then used to bioconvert Δ⁹,11 -androstenedione in shake flasks at 10 g/liter cells and 10 g/liter steroid.

    ______________________________________                                         Comparison of Bioconversion Capacity of A. simplex                             Cells Dried by Different Methods                                                Cell Type  (Hours)SamplingTime of                                                                  SubstrateResidual%                                                                      ##STR3##                                         ______________________________________                                         Acetone-dried                                                                                1      98.7    .013                                                            4      95.5    .011                                                           24      84.1*   .007                                              Heat-dried    1      85.1    .149                                                            4      23.2    .192                                                           24       7.2*   .039                                              ______________________________________                                          .sup.+ Bioconversion activity is calculated as follows:                        ##STR4##                                                                       g product formed/hours of incubation/g cells added = activity                  *Residual levels did not decrease with further incubation.               

EXAMPLE 6

By substituting the following listed substrates for 6α-methyl hydrocortisone in Example 1, or androsta-4,9(11)-diene,3,17-dione in Example 2, there are obtained the corresponding listed products:

Substrates

1. 21-acetoxy-9α-fluoro-11β,16α,17-trihydroxy-pregn4-ene-3,20-dione;

2. 21-acetoxy-6α,9α-difluoro-11β,16α,17-trihydroxy-pregn-4-ene-3,20-dione-16,17 -acetonide;

3. 21-acetoxy-6α-fluoro-11β-hydroxy-16α-methyl-pregn-4-ene-3,20-dione;

4. 21-acetoxy-6α-fluoro-11β,17-hydroxy-pregn-4-ene-3,20-dione;

5. 21-acetoxy-6α,9α-difluoro-11β,17-dihydroxy-16α-methyl-pregn-4-ene-3,20-dione;

6. 21-acetoxy-9α-fluoro-11β,16α,17trihydroxy-pregn-4-ene-3,20-dione-16,17-acetonide;

7. 21-acetoxy-9β,11α-epoxy-6α-fluoro-16α,17-dihydroxy-pregn-4-ene-3,20-dione-16,17-acetonide;

8. 21-acetoxy-9β,11β-epoxy-16α-hydroxy-pregn-4-ene-3,20-dione

9. 21-acetoxy-9β,11β-epoxy-16α,17-dihydroxy-pregn-4-ene-3,20-dione-16,17-acetonide;

Products

1. 21-acetoxy-9α-fluoro-11β,16α,17 -trihydroxy-pregn-1,4-diene-3,20-dione and 9α-fluoro-11β,16α,17,21-tetrahydroxy-pregn-1,4-diene-3,20-dione;

2. 21-acetoxy-6α,9α-difluoro-11β,16α,17-trihydroxy-pregn-1,4-diene-3,20-dione-16,17-acetonide and 6α,9α-fluoro-11β, 16α,17,21-tetrahydroxy-pregn-1,4-diene-3,20-dione-16,17-acetonide;

3. 21-acetoxy-6α-fluoro-11β-hydroxy-16α-methyl-pregn-1,4-diene-3,20-dione and 6α-fluoro-11β,21-dihydroxy-16α-methyl-pregn-1,4-diene-3,20-dione;

4. 21-acetoxy-6αfluoro-11β,17-hydroxy-pregn-1,4-diene-3,20-dione and 6α-fluoro-11β,17,21-trihydroxy-1,4-diene-3,20-dione;

5. 21-acetoxy-6α,9α-difluoro-11β,17-dihydroxy-16α-methyl-pregn-1,4-diene-3,20-dione and 6α,9α-difluoro-11β,17,21-trihydroxy-1,4-diene-3,20-dione;

6. 21-acetoxy-9α-fluoro-11β,16α,17-trihydroxy-pregn-1,4-diene-3,20-dione-16,17-acetonide;

7. 21acetoxy-9β,11β-epoxy-6α-fluoro-16α,17-dihydroxy-pregn-1,4-diene-3,20-dione-16,17-acetonide;

8. 21acetoxy-9β,11β-epoxy-16-hydroxy-pregn-1,4-dien e-3,20-dione and 9β,11β-epoxy-16α,21-dihydroxy-pregn-1,4-diene-3,20-dione;

9. 21acetoxy-9β,11β-epoxy-16α,17-dihydroxy-pregn -1,4-diene-3,20-dione-16,17-acetonide.

EXAMPLE 7 Bioconversion of 11β-hydroxy-androsta-4-ene-3,17-dione

One gram of dried A. simplex cells, prepared as described in Example 2, was resuspended in 100 ml 50 mM phosphate buffer pH 7.5. Menadione, dissolved in 3A ethanol, was added to a final concentration of 86 mg/liter. One-half gram of 11β-hydroxy-androstenedione was added to the flask. The mixture was incubated on a rotary shaker at 31° C. When sampled after 1-day's incubation, two products were observed by thin layer chromatography of a methylene chloride extract. Approximately 95% of the steroid was present in 11β-hydroxy-androsta-1,4-diene-3,17-dione. The remainder was unconverted substrate.

EXAMPLE 8

Upon following the conditions of Example 7, the following androstenedione derivatives that are modified at the C-11 position can be 1-dehydrogenated to the products shown:

    ______________________________________                                         Substrate → Product                                                     ______________________________________                                         (1)   11β-hydroxy-16β-methyl-androsta-4-ene-3,17-dione                     →                                                                       11β-hydroxy-16β-methyl-androsta-1,4-diene-3,17-dione           (2)   11β-hydroxy-16α-methyl-androsta-4-ene-3,17-dione                    →                                                                       11β-hydroxy-16α-methyl-androsta-1,4-diene-3,17-dione          (3)   6α-fluoro-11β-hydroxy-androsta-4-ene-3,17-dione                     →                                                                       6α-fluoro-11β-hydroxy-androsta-1,4-diene-3,17-dione           (4)   6α-methyl-11β-hydroxy-androsta-4-ene-3,17-dione                     →                                                                       6α-methyl-11β-hydroxy-androsta-1,4-diene-3,17-dione           (5)   11α-hydroxy-androsta-4-ene-3,17-dione → 11α-hydro           xy-                                                                            androsta-1,4-diene-3,17-dione                                            (6)   androsta-4-ene-3,11,17-trione → androsta-1,4-diene-                     3,11,17-trione.                                                          ______________________________________                                    

The utility of 1,2-dehydro steroids is well known. For example, see U.S. Pat. No. 3,284,447, which discloses the utility of Δ¹,4,9(11) pregnetrienes in the synthesis of diurectic corticosteroids substituted at carbon 16. U.S. Pat. No. 4,041,055 discloses a process for the synthesis of corticosteroids from Δ¹,4 -androstenedione derivatives, demonstrating the utility of 1,2-dehydroandrostenes as important intermediates in the production of medically useful steroids. 

We claim:
 1. A process for preparing a 1,2-dehydro-Δ⁴ -3-keto steroid selected from the group consisting of ##STR5## R₆ is a hydrogen or fluorine atom or methyl group. R₆ ' is a hydrogen atom or methyl group.R₉ is nothing, a hydrogen, fluorine or oxygen atom which makes the C ring(a) Δ⁹(11) when R₉ is nothing and (b) 9β,11β-epoxide when R₉ is an oxygen atom; R₁₁ is a hydrogen or oxygen atom, two hydrogen atoms, or α- or β-hydroxyl group which makes the C-ring(a) Δ⁹(11) when R₁₁ is a hydrogen atom, (b) 9β,11β-epoxide when R₁₁ is an oxygen atom and between C₁₁ and R₁₁ is a single bond, and (c) a ketone when R₁₁ is an oxygen atom and between C₁₁ and R₁₁ is a double bond; indicates that the attached group can be in either the α or 62 configuration; is a single or double bond; R_(1l) 40 is a β-hydroxyl group, an oxygen atom (11-ketone), or hydrogen atom (Δ⁹(11)); R₁₆ is a hydrogen atom or methyl group; R₁₆ ' is a hydrogen atom, methyl or hydroxyl group, when R₁₆ ' is an α-hydroxyl group the 16α and 17α-hydroxyl groups can be in the form of an acetonide; R₂₁ is a hydrogen atom or --OC--OR₂₁ 40; R₂₁ ' is methyl, ethyl, or phenyl which comprises exposing the corresponding 1,2-saturated-Δ⁴ -3 keto steroid to air-dried or heat-dried cells of Arthrobacter simplex having a moisture content of about 1 to about 10% where the cells are dried in the absence of an organic solvent.
 2. A process according to claim 1 where the 1,2-dehydro-Δ⁴ -3-keto steroid or 21-monoester thereof is selected from the group consisting of1. 6α-methylprednisolone
 2. Androsta-1,4,9(11)-triene-3,17-dione
 3. androsta-1,4-diene-3,17-dione
 4. 6α-fluoroandrosta-1,4,9(11)-triene-3,17-dione
 5. 6α-methylandrosta-1,4,9(11)-triene-3,17-dione
 6. 16β-methylandrosta-1,4,9(11)-triene-3,17-dione
 7. 17α-hydroxypregna-1,4-diene-20-yn-3-one
 8. 17α-hydroxypregna-1,4,9(11)-triene-20-yn-3-one
 9. 17α-hydroxy-16β-methylpregna-1,4,9(11)-triene-20-yn-3-one
 10. 11β,21-dihydroxypregna-1,4,17(20-trien-3-one
 11. 21-acetoxy-11β-hydroxypregna-1,4,17(20)-trien-3-one
 12. 6α-methyl-11β,21-dihydroxypregna-1,4,17(20)-trien3-one
 13. 20-chloropregna-1,4,9(11),17(20)-tetraen-21-al-3-one
 14. prednisolone
 15. 21-acetoxy-11β,17-dihydroxy-16β-methylpregna-1,4-diene-3,20-dion
 16. 11β,17,21-trihydroxy-16β-methylpregna-1,4-diene-3,20-dione
 17. 21-acetoxy-9α-fluoro-11β,17dihydroxy-16β-methylpregna-1,4-diene-3,20-dione
 18. 9α-fluoro-11β,17,21-trihydroxy-16β-methylpregna-1,4-diene-3,20-dione
 19. 21-acetoxy-9β, 11β-epoxy-17-hydroxy-16β-methylpregna-1,4-diene-3,20-dione
 20. 9β,11β-epoxy-17,21-dihydroxy-16β-methylpregna-1,4-diene-3,20-dione 21 . 21-acetoxy-17-hydroxypregna-1,4,9(11)-triene-3,20-dione
 22. 17,21-dihydroxypregna-1,4,9(11)-triene-3,20-dione
 23. 21-acetoxy-16α,17-dihydroxypregna-1,4,9(11)-triene-3,20-dione
 24. 16α,17,21-trihydroxypregna-1,4,9(11)-triene-3,20-dione
 25. 21-acetoxy-17-hydroxy-16α-methylprega-1,4,9(11)-triene-3,20-dione26. 17,21-dihydroxy-16α-methylpregna-1,4,9(11)-triene3,20-dione
 27. 21-benzoyloxy-17-hydroxy-16β-methylpregna-1,4,9(11)-triene-3,20-dione
 28. 21-acetoxy-17-hydroxy-16β-methylpregna-1,4,9(11)-triene-3,20-dione
 29. 17,21-dihydroxy-16β-methylpregna-1,4,9(11)-triene-3,20-dione
 30. 21-acetoxypregna-1,4,9(11),16-tetraene-3,20-dione
 31. 21-hydroxypregna-1,4,9(11),16-tetraene-3,20-dione
 32. 21-acetoxy-6α-fluoropregna-1,4,9(11),16-tetraene-3,20-dione
 33. 6α-fluoro-21-hydroxypregna-1,4,9(11), 16-tetraene-3,20-dione
 34. 21-acetoxy-9α-fluoro-11β,16α,17-trihydroxypregna-1,4-diene-3,20-dione
 35. 9α-fluoro-11β,16α,17,21-tetrahydroxypregna-1,4-diene-3,20-dione
 36. 21-acetoxy-6α,9α-difluoro-11β,16α,17-trihydroxypregna-1,4-diene-3,20-dione-16,17-acetonide
 37. 6α,9α-fluoro-11β,16α,17,21-tetrahydroxypregna-1,4-diene-3,20-dione 16,17-acetonide
 38. 21-acetoxy-6α-fluoro-11β-hydroxy-16α-methylpregna-1,4-diene-3,20-dione
 39. 6α-fluoro-11β,21-dihydroxy-16α-methylpregna-1,4-diene-3,20-dione
 40. 21-acetoxy-6α-fluoro-11α,17-hydroxypregna-1,4-diene-3,20-dione
 41. 6α-fluoro-11β,17,21-trihydroxy-1,4-diene-3,20-dione
 42. 21-acetoxy-6α,9α-difluoro-11β, 17-dihydroxy-16α-methylpregna-1,4-diene-3,20-dione
 43. 6α,9α-difluoro-11β,17,21-trihydroxy-1,4-diene-3,20-dione
 44. 21-acetoxy-9α-fluoro-11α,16α,17-trihydroxypregna-1,4-diene-3,20-dione 16,17-acetonide
 45. 21-acetoxy-9β, 11β-epoxy-6α-fluoro-16α, 17-dihydroxypregna-1,4-diene,3,20-dione-16,17-acetonide
 46. 21-acetoxy-9β,11β-expoxy-16-hydroxypregna-1,4-diene-3,20-dione
 47. 9β,11β-epoxy-16β, 21-dihydroxypregna-1,4-diene-3,20-dione;
 48. 21-acetoxy-9β,11β-epoxy-16α,17-dihydroxypregna-1,4-diene-3,20-dione 16,17acetonide
 49. 11β, -hydroxyandrosta-1,4-diene-3,17-dione50. 11β,-hydroxy-16β, -methylandrostra-1,4-diene-3,17dione
 51. 11β-hydroxy-16α-methylandrostra-1,4-diene-3,17-dione
 52. 6α-fluoro-11β-hydroxyandrosta-1,4-diene-3,17-dione
 53. 6α-methyl-11β-hydroxyandrosta-1,4-diene-3,17-dione
 54. 11α-hdyroxyandrosta-1,4-diene-3,17-dione
 55. androsta-1,4-diene-3,11,17-trione.
 3. A process according to claim 2 where the 1,2-dehydro-Δ⁴ -3-keto steroid or 21-monoester thereof is selected from the group consisting of 6α-methylprednisolone, androsta-1,4,9(11)-triene-3,17-dione, androsta-1,4-diene-3,17-dione, 16β-methylandrosta-1,4,9-(11)-triene-3,17-dione, prednisolone, 17,21-dihydroxypregna-1,4,9(11)-triene-3,20-dione, 21-acetoxy-16α,17-dihydroxypregna-1,4,9(11)-triene-3,20-dione, 16α,17,21-trihydroxypregna-1,4,9(11)-triene-3,20-dione, 21-acetoxypregna-1,4,9(11),16-tetraene-3,20-dione, 21-hydroxypregna-1,4,9(11),-16-tetraene-3,20-dione, 21-acetoxy-6α-fluoropregna-1,4,9(11),16-tetraene-3,20-dione, 6α-fluoro-11β,17,21-trihydroxyl-1,4-diene-3,20-dione, 11β-hydroxyandrosta-1,4-diene-3,17-dione, 11β-hydroxy-16β-methylandrosta-1,4-diene-3,17-dione.
 4. A process according to claim 2 where the 1,2-dehydro-Δ⁴ -3-keto steroid or 21-monoester thereof is selected from the group consisting of 21-acetoxy-90α-fluoro-11β,17-dihydroxy-16β-methylpregna-1,4-diene-3,20-dione, 9α-fluoro-11β,17,21-trihydroxy-16β-methylpregna-1,4-diene-3,20-dione, 21-acetoxy-17-hydroxy-16α-methylpregna-1,4,9(11)-triene-3,20-dione,17,21-dihydroxy-16α-methylpregna-1,4,9(11)-triene-3,20-dione, 21-acetoxy-9α-fluoro-11β,16α,17-trihydroxypregna-1,4-diene-3,20-dione, 9α-fluoro-11β,16α,17,21-tetrahydroxypregna-1,4-diene-3,20-dione, 21-acetoxy-6α,9α-difluoro-11β,16α,17-trihydroxypregna-1,4-diene-3,20-dione-16,17-acetonide, 6α,9α-fluoro-11β,16α,17,21-tetrahydroxypregna-1,4-diene-3,20-dione 16,17-acetonide, 21-acetoxy-6α-fluoro-11β-hydroxy-16α-methylpregna-1,4-diene-3,20-dione, 6α-fluoro-11β,21-dihydroxy-16α-methylpregna-1,4-diene-3,20-dione, 21-acetoxy-6α-fluoro-11β,17-hydroxypregna-1,4-diene-3,20-dione, 21-acetoxy-6α,9α -difluoro-11β,17-dihydroxy-16α-methylpregna-1,4-diene-3,20-dione, 21-acetoxy-9α-fluoro-11β,16α,17-trihydroxypregna-1,4-diene-3,20-dione 16,17-acetonide, 21-acetoxy9β,11β-epoxy-6α-fluoro-16α,17-dihydroxypregna-1,4-diene-3,20-dione 16,17-acetonide, 21-acetoxy-9β,11β-epoxy-16-hydroxypregna-1,4-diene-3,20-dione, 9β,11β-epoxy-16α,21-dihydroxypregna-1,4-diene-3,2-dione, 21-acetoxy-9β,11β-epoxy-16α,17-dihydroxypregna-1,4-diene-3,20-dione 16,17-acetonide, 11β-hydroxy-16α-methylandrosta-1,4-diene-3,17-dione, 11α-hydroxyandrosta-1,4-diene-3,17-dione, androsta-1,4-diene-3,11,17-trione.
 5. A process according to claim 1 which is performed in the presence of an exogenous electron carrier.
 6. A process according to claim 5, where the exogenous electron carrier is selected from the group consisting of menadione, phenazine methosulfate, dichlorophenolindophenol, 1,4-naphthoquinone, menadione bisulfite, ubiquinones (Coenzyme Q), or vitamin K-type compounds.
 7. A process according to claim 6 where the exogenous electron carrier is selected from the group consisting of menadione, phenazine methosulfate, dichlorophenolidophenol, 1,4-napthoquinone or menadione bisulfite.
 8. A process according to claim 7 where the exogenous electron carrier is menadione. 